U.S. patent application number 11/187903 was filed with the patent office on 2005-11-17 for communication system with mobile terminal accessible to mobile communication network and local network simultaneously.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. Invention is credited to Inoue, Atsushi.
Application Number | 20050255880 11/187903 |
Document ID | / |
Family ID | 18759563 |
Filed Date | 2005-11-17 |
United States Patent
Application |
20050255880 |
Kind Code |
A1 |
Inoue, Atsushi |
November 17, 2005 |
Communication system with mobile terminal accessible to mobile
communication network and local network simultaneously
Abstract
In a communication system using a mobile terminal capable of
accessing both a mobile communication network and a local network
simultaneously and a gateway provided between a fixed communication
network and the local network, the mobile terminal transmits an
inquiry message for inquiring information regarding a location on
networks of a correspondent of packet communications, to the
gateway through the local network, and receives a response message
indicating the lookup processing result from the gateway through
the local network. Then, the mobile terminal acquires an address to
be used in the packet communications with the correspondent
according to the response message, and assigns the address to a
communication interface for the local network.
Inventors: |
Inoue, Atsushi; (Kanagawa,
JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
KABUSHIKI KAISHA TOSHIBA
Tokyo
JP
|
Family ID: |
18759563 |
Appl. No.: |
11/187903 |
Filed: |
July 25, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11187903 |
Jul 25, 2005 |
|
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09947512 |
Sep 7, 2001 |
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Current U.S.
Class: |
455/552.1 ;
455/73 |
Current CPC
Class: |
H04L 29/12915 20130101;
H04L 29/12254 20130101; H04L 61/6077 20130101; H04L 2012/2841
20130101; H04W 88/06 20130101; H04L 12/283 20130101; H04L 61/6059
20130101; H04L 29/12952 20130101; H04L 61/2092 20130101; H04L
61/2084 20130101; H04W 40/02 20130101; H04W 88/16 20130101; H04W
48/14 20130101; H04L 61/2038 20130101; H04L 12/5692 20130101; H04L
29/1232 20130101; H04W 80/00 20130101; H04W 8/26 20130101; H04L
29/12311 20130101 |
Class at
Publication: |
455/552.1 ;
455/073 |
International
Class: |
H04B 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 8, 2000 |
JP |
2000-273659 |
Claims
1-3. (canceled)
4. A mobile terminal device capable of accessing both a mobile
communication network and a local network simultaneously, the
mobile terminal device comprising: a first communication interface
provided with respect to the mobile communication network; a second
communication interface provided with respect to the local network;
a packet communication unit configured to carry out first packet
communications through the first communication interface and second
packet communications through the second communication interface;
an inquiry message transmission unit configured to transmit an
inquiry message for inquiring information regarding a location on
networks of a correspondent of packet communications to be carried
out, through the second communication interface; and an address
assignment unit configured to receive a response message in
response to the inquiry message through the second communication
interface, acquire an address to be used by the mobile terminal
device in the packet communications with the correspondent
according to the response message, and assign the address to the
second communication interface.
5. The mobile terminal device of claim 4, further comprising: a
judgment unit configured to judge a manner of utilizing the first
packet communications and the second packet communications
according to a prescribed policy, when both the first packet
communications and the second packet communications are
possible.
6. The mobile terminal device of claim 5, wherein when the address
assignment unit assigns one global address to the second
communication interface while the mobile terminal device is already
connected to the mobile communication network by using another
global address through the first communication interface, the
judgment unit judges which one of the first packet communications
using the another global address via the mobile communication
network through the first communication interface and the second
packet communications using the one global address via the local
network through the second communication interface should be used,
by accounting for at least one of a state, a performance or a
charging condition of the mobile communication network and a state,
a performance or a charging information of an external
communication network to which the local network is connected.
7. The mobile terminal device of claim 4, wherein the address
assignment unit assigns a link local address as defined in IPv6 to
the second communication interface when the location of the
correspondent is on-link, assigns a site local address as defined
in IPv6 to the second communication interface when the location of
the correspondent is within a site accessible from the second
communication interface, or assigns a global address to the second
communication interface otherwise.
8. The mobile terminal device of claim 4, wherein the packet
communication unit releases an entire network setting on the mobile
communication network side or change a network setting of all
applications on the mobile terminal device to a network setting on
the local network side, when all services received through the
first communication interface via the mobile communication network
are finished after accessing the local network through the second
communication interface.
9. The mobile terminal device of claim 4, wherein the packet
communication unit has a gateway function for relaying packet
communications of another device connected to the local network by
using the first communication interface and the second
communication interface, when both the first packet communications
through the first communication interface and the second packet
communications through the second communication interface are
possible.
10. The mobile terminal device of claim 4, wherein the second
communication interface supports Bluetooth as the local
network.
11. The mobile terminal device of claim 4, further comprising a
voice communication unit configured to carry out voice
communications.
12-16. (canceled)
17. An address assignment method for a mobile terminal device
capable of accessing both a mobile communication network and a
local network simultaneously, the method comprising: transmitting
an inquiry message for inquiring information regarding a location
on networks of a correspondent of packet communications to be
carried out, from the mobile terminal device through the local
network; and receiving a response message in response to the
inquiry message through the local network at the mobile terminal
device; acquiring an address to be used by the mobile terminal
device in the packet communications with the correspondent
according to the response message; and assigning the address to a
communication interface for the local network at the mobile
terminal device.
18. (canceled)
19. A computer program product for causing a computer of a mobile
terminal device capable of accessing both a mobile communication
network and a local network simultaneously, to execute an address
assignment, the computer program product comprising: first computer
program codes for causing the computer to transmit an inquiry
message for inquiring information regarding a location on networks
of correspondent of packet communications to be carried out, from
the mobile terminal device through the local network; second
computer program codes for causing the computer to receive a
response message in response to the inquiry message through the
local network; third computer program codes for causing the
computer to acquire an address to be used by the mobile terminal
device in the packet communications with the correspondent
according to the response message; and fourth computer program
codes for causing the computer to assign the address to a
communication interface for the local network at the mobile
terminal device.
20. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a mobile communication
system using a mobile terminal device which is capable of accessing
both a mobile communication network and a local network
simultaneously and a gateway device for relaying between a fixed
communication network and a local network.
[0003] 2. Description of the Related Art
[0004] In conjunction with the rapid spread of cellular phones and
the Internet, the Internet service using a cellular phone as a
terminal has been developed by the mobile communication service
providers. This is a service in which a module for processing a
communication protocol called TCP/IP used in the Internet is
provided in the cellular phone so as to enable WWW service, e-mail
delivery, static image and video image data transfer, etc. This
service has an advantage in that it becomes possible to freely
access not just information closed within the communication service
provider but also various information available on the Internet
that is spreading worldwide, and for this reason the number of
users of this service is increasing rapidly.
[0005] Now, the cellular phone Internet service that has an
enormous number of users encounters a serious problem regarding how
to assign addresses to terminals. Currently, the Internet faces
with the problem of IP address shortage in view of the ever
increasing number of nodes (routers and terminals), and in the
current IPv4, it has been customary to use an address system called
private address that is closed within an organization for accesses
in an enterprise network and to use global addresses only for
accesses to the external of the organization by utilizing the
address conversion. Similarly, in the case of the cellular phone
Internet service, it is currently customary to use the private
address within the cellular phone network by providing an address
conversion device (NAT: Network Address Translator) at a border
between the IP packet network of the cellular phone company and the
global Internet.
[0006] On the other hand, the next generation IP specification
called IPv6 is currently under the development. The IPv6 can
accommodate far more nodes compared with the IPv4 by expanding the
IP address from a 32 bits width as used in the IPv4 to a 128 bits
width. Similarly, in the case of the cellular phone Internet
service, it is possible to assign unique global addresses to all
terminals by adopting the IPv6. In this way, communications using a
seamless end-to-end connection that does not require a relay device
such as NAT on the communication path can be realized by using a
wide address space, and it is expected to be advantageous in many
aspects including the security and the quality of service (QoS).
Also, the IPv6 has a function called address autoconfiguration for
automatically generating an address from a network ID managed by
each router and a unique ID of the device, and this is expected to
make the management of hosts easier.
[0007] Also, recently, in conjunction with the advance of the
wireless technology, the techniques for locally connecting various
types of devices by a wireless network have been developed. One
such technique is the wireless standard called Bluetooth which
connects devices in short distances by using 2.4 GHz unlicensed
radio band. In the Bluetooth, devices can carry out mutual data
communications by forming an ad-hoc network called pico-net. The
similar network specification also includes the HomeRF which is
intended for use in the home network.
[0008] Now, using the IPv6 with the above described features, it is
possible to consider a situation where a portable terminal is
capable of both the Internet access via the cellular phone network
and the Internet access via the ISP (Internet Service Provider)
network from a home network or a local network such as the
Bluetooth or the like. In such a situation, when the portable
terminal starts the Internet communications using either the
cellular phone network or the local network+the ISP network, the
setting of the portable terminal can be made according to commands
from a router device on the cellular phone network or a router
device on the ISP network. However, in the case where the portable
terminal receives a service from the cellular phone network side
while it also moves into the local network and carries out
communications through the local network, there is a need to
determine which one of the Internet access via the cellular phone
network and the Internet access via the local network+the ISP
network should be selected, and how the setting for it should be
made, according to some policy.
BRIEF SUMMARY OF THE INVENTION
[0009] It is therefore an object of the present invention to
provide a mobile communication system in which each mobile terminal
device is capable of making reasonable judgement and setting
regarding the necessary address setting, appropriate communication
route selection, etc., in the case of moving into the local network
while receiving the communication service on the mobile
communication network.
[0010] According to one aspect of the present invention there is
provided a communication system, comprising: a mobile terminal
device capable of accessing both a mobile communication network and
a local network simultaneously; and a gateway device provided
between a fixed communication network and the local network; the
mobile terminal device having: an inquiry message transmission unit
configured to transmit an inquiry message for inquiring information
regarding a location on networks of a correspondent of packet
communications to be carried out, through the local network; the
gateway device having: a lookup unit configured to carry out a
lookup processing to determine whether the location of the
correspondent on networks is on the local network, or within same
management domain on the fixed communication network as the mobile
terminal device and outside the local network, or outside the same
management domain on the fixed communication network, upon
receiving the inquiry message from the mobile terminal device
through the local network; and a transmission unit configured to
transmit a result of the lookup processing obtained by the lookup
unit as a response message to the mobile terminal device through
the local network; and the mobile terminal device also having: an
address assignment unit configured to receive the response message
from the gateway device through the local network, acquire an
address to be used by the mobile terminal device in the packet
communications with the correspondent according to the response
message, and assign the address to a communication interface for
the local network.
[0011] According to another aspect of the present invention there
is provided a mobile terminal device capable of accessing both a
mobile communication network and a local network simultaneously,
the mobile terminal device comprising: a first communication
interface provided with respect to the mobile communication
network; a second communication interface provided with respect to
the local network; a packet communication unit configured to carry
out first packet communications through the first communication
interface and second packet communications through the second
communication interface; an inquiry message transmission unit
configured to transmit an inquiry message for inquiring information
regarding a location on networks of a correspondent of packet
communications to be carried out, through the second communication
interface; and an address assignment unit configured to receive a
response message in response to the inquiry message through the
second communication interface, acquire an address to be used by
the mobile terminal device in the packet communications with the
correspondent according to the response message, and assign the
address to the second communication interface.
[0012] According to another aspect of the present invention there
is provided a gateway device provided between a fixed communication
network and a local network, for relaying communications of a
mobile terminal device capable of accessing both a mobile
communication network and the local network simultaneously, the
gateway device comprising: a first communication interface provided
with respect to the fixed communication network; a second
communication interface provided with respect to the local network;
a packet communication unit configured to carry out first packet
communications through the first communication interface and second
packet communications through the second communication interface; a
lookup unit configured to carry out a lookup processing to
determine whether a location of a prescribed device or service on
networks is on the local network, or within same management domain
on the fixed communication network as a mobile terminal device and
outside the local network, or outside the same management domain on
the fixed communication network, upon receiving an inquiry message
for inquiring information regarding the location of the prescribed
device or service on networks from the mobile terminal device
through the second communication interface; and a transmission unit
configured to transmit a result of the lookup processing obtained
by the lookup unit as a response message to the mobile terminal
device through the second communication interface.
[0013] According to another aspect of the present invention there
is provided an address assignment method for a mobile terminal
device capable of accessing both a mobile communication network and
a local network simultaneously, the method comprising: transmitting
an inquiry message for inquiring information regarding a location
on networks of a correspondent of packet communications to be
carried out, from the mobile terminal device through the local
network; and receiving a response message in response to the
inquiry message through the local network at the mobile terminal
device; acquiring an address to be used by the mobile terminal
device in the packet communications with the correspondent
according to the response message; and assigning the address to a
communication interface for the local network at the mobile
terminal device.
[0014] According to another aspect of the present invention there
is provided a lookup service method of a gateway device provided
between a fixed communication network and a local network, for
relaying communications of a mobile terminal device capable of
accessing both a mobile communication network and the local network
simultaneously, the method comprising: carrying out a lookup
processing to determine whether a location of a prescribed device
or service on networks is on the local network, or within same
management domain on the fixed communication network as a mobile
terminal device and outside the local network, or outside the same
management domain on the fixed communication network, upon
receiving an inquiry message for inquiring information regarding
the location of the prescribed device or service on networks from
the mobile terminal device through the local network at the gateway
device; and transmitting a result of the lookup processing as a
response message to the mobile terminal device through the local
network from the gateway device.
[0015] According to another aspect of the present invention there
is provided a computer program product for causing a computer of a
mobile terminal device capable of accessing both a mobile
communication network and a local network simultaneously, to
execute an address assignment, the computer program product
comprising: first computer program codes for causing the computer
to transmit an inquiry message for inquiring information regarding
a location on networks of a correspondent of packet communications
to be carried out, from the mobile terminal device through the
local network; second computer program codes for causing the
computer to receive a response message in response to the inquiry
message through the local network; third computer program codes for
causing the computer to acquire an address to be used by the mobile
terminal device in the packet communications with the correspondent
according to the response message; and fourth computer program
codes for causing the computer to assign the address to a
communication interface for the local network at the mobile
terminal device.
[0016] According to another aspect of the present invention there
is provided a computer program product for causing a computer of a
gateway device provided between a fixed communication network and a
local network, for relaying communications of a mobile terminal
device capable of accessing both a mobile communication network and
the local network simultaneously, to provide a lookup service, the
computer program product comprising: first computer program codes
for causing the computer to carry out a lookup processing to
determine whether a location of a prescribed device or service on
networks is on the local network, or within same management domain
on the fixed communication network as the mobile terminal device
and outside the local network, or outside the same management
domain on the fixed communication network, upon receiving an
inquiry message for inquiring information regarding the location of
the prescribed device or service on networks from the mobile
terminal device through the local network; and second computer
program codes for causing the computer to transmit a result of the
lookup processing as a response message to the mobile terminal
device through the local network.
[0017] Other features and advantages of the present invention will
become apparent from the following description taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a block diagram showing an exemplary configuration
of a communication system according to one embodiment of the
present invention.
[0019] FIG. 2 is a block diagram showing an exemplary configuration
of a gateway device in the communication system of FIG. 1.
[0020] FIG. 3 is a block diagram showing an exemplary configuration
of a mobile terminal device in the communication system of FIG.
1.
[0021] FIG. 4 is a flow chart showing an exemplary processing
procedure for one operation by the mobile terminal device of FIG.
3.
[0022] FIG. 5 is a block diagram showing a part of the
communication system of FIG. 1 for explaining one exemplary
operation that can be carried out.
[0023] FIG. 6 is a block diagram showing a part of the
communication system of FIG. 1 for explaining another exemplary
operation that can be carried out.
[0024] FIG. 7 is a flow chart showing an exemplary processing
procedure for another operation by the mobile terminal device of
FIG. 3.
[0025] FIG. 8 is a flow chart showing an exemplary processing
procedure for another operation by the mobile terminal device of
FIG. 3.
[0026] FIG. 9 is a flow chart showing an exemplary processing
procedure for another operation by the mobile terminal device of
FIG. 3.
[0027] FIG. 10A is a diagram showing an exemplary packet header to
be used in a method for switching a belonging network according to
Mobile IPv6.
[0028] FIG. 10B is a schematic diagram for explaining a method for
switching a belonging network according to Mobile IPv6.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Referring now to FIG. 1 to FIGS. 10A and 10B, one embodiment
of a mobile communication system according to the present invention
will be described in detail.
[0030] FIG. 1 shows an exemplary configuration of a communication
system according to this embodiment.
[0031] In FIG. 1, a region enclosed by a dashed line 12 corresponds
to a mobile carrier network portion, while a region enclosed by a
chain line 11 corresponds to a home network portion.
[0032] In the following, the exemplary case where a mobile terminal
device 20 moves into the home network 11 while carrying out
communications through the mobile carrier network 12 will be mainly
described.
[0033] In the mobile carrier network 12, a plurality of network
links are connected through a cellular phone network 6 and router
devices 4. Each router device 4 has at least functions of an
ordinary router compatible with the IPv6.
[0034] The mobile carrier network 12 is assumed to be originally
providing the ordinary voice communication service, but a
configuration for providing the ordinary voice communication
service is omitted in FIG. 1. Note that this embodiment is directed
to the exemplary case where one mobile carrier manages its own
packet communication network as a single management domain, but
there can also be cases where one mobile carrier has a plurality of
management domains, cases where a plurality of mobile carriers have
a single common management domain, and any combination of these
cases.
[0035] The mobile terminal device 20 (such as a portable terminal
or a cellular phone, for example) will be connected to the
corresponding network link through a wireless base station 5
corresponding to a geographic location of the mobile terminal
device 20. Then, the mobile terminal device 20 becomes capable of
carrying out packet communications according to the IPv6 with a
node located within the same network link, a node within the same
management domain through the router device 4, or a node (such as a
server 8, for example) located outside the management domain
through the router device 4 and the Internet 7.
[0036] On the other hand, in the home network 11, various types of
devices 2 and a gateway 1 are connected through a home local
network 3. The mobile terminal device 20 has a function for
accessing this home local network 3.
[0037] Also, the gateway device 1 is assumed to be connected to the
external Internet 7 through a fixed communication network 9 (which
is assumed to be an ISP network here). Note that this embodiment is
directed to the exemplary case where one Internet service provider
manages its own range for providing the Internet connection service
as a single management domain, but there can also be cases where
one service provider has a plurality of management domains, cases
where a plurality of service providers have a single common
management domain, and any combinations of these cases.
[0038] The mobile terminal device 20 and the devices 2 connected to
the home local network 3 are capable of carrying out packet
communications according to the IPv6 with the server 8 on the
Internet 7 through the gateway device 1 and the ISP network 9. In
addition, they are also capable of carrying out packet
communications according to the IPv6 with a server 10 for providing
services limited only to members within the ISP network 9, for
example, when such a server 10 exists.
[0039] In this embodiment, the home local network 3 is assumed to
be a local wireless network such as Bluetooth, for example.
[0040] Note that, in FIG. 1, the dashed line 12 and the chain line
11 are depicted only for the sake of explaining the basic
configuration logically, and they do not indicate an area covered
by the wireless network. In this embodiment mobile terminal device
20 is assumed to be capable of accessing both the mobile carrier
network 12 and the home local network 3 simultaneously.
[0041] FIG. 2 shows an exemplary configuration of the gateway
device 1 in this embodiment.
[0042] As shown in FIG. 2, this gateway device 1 comprises a first
communication interface 31 for accessing the ISP network 9, a
second communication interface 32 for accessing the home local
network 3, a data relay unit 33 for relaying between the first and
second communication interfaces 31 and 32, a service database 34, a
service lookup function unit 35, and a network monitoring unit 36.
If necessary, the data relay device 33 may include a function for
carrying out a protocol conversion, a media conversion, etc., at a
time of relaying between the first and second communication
interfaces 31 and 32.
[0043] The service lookup function unit 35 is operated when a
service lookup inquiry message is received through the the second
communication interface 32, to look up the requested service
through the service database 34 or inquire the requested service to
another server and returns the lookup result to the inquiring
source.
[0044] The network monitoring unit 36 is operated when a network
state inquiry message is received through the second communication
interface 32, to returns a message containing information on a
network state of the ISP network 9 side to the inquiring
source.
[0045] Note that the gateway device 1 may also have functions as
the IPv6 compatible router in the home local network 3, or another
IPv6 compatible router may be provided in the home local network
3.
[0046] FIG. 3 shows an exemplary configuration of the mobile
terminal device 20 in this embodiment.
[0047] As shown in FIG. 3, this mobile terminal device 20 comprises
a first communication interface 24 for accessing the mobile carrier
network 12, a second communication interface 25 for accessing the
home local network 3, a voice communication unit 21 for carrying
out ordinary voice communications, a packet communication unit 22
for carrying out packet communications according to the IPv6, an
address register 23, an application list 26, and an active register
27.
[0048] The mobile terminal device 20 is capable of relating a
plurality of IPv6 addresses with respect to the same communication
interface (capable of sending packets by using a plurality of IPv6
addresses from the same communication interface). The address
register 23 is used for the purpose of storing these addresses.
[0049] A various IPv6 applications are to be operated on the mobile
terminal device 20 side, and an application list 26 is used for
storing a list of these applications (which includes information
for identifying each application (a file name, for example) and an
application type of each application, for example).
[0050] Also, when the specific application is activated by the
user, the active register 27 registers information regarding the
currently operated application (such as information for identifying
that application, application type of that application, and
information for indicating a communication interface used for that
application (either the first communication interface or the second
communication interface), for example).
[0051] Here, the address scope defined in the IPv6 will be
described (see RFC 2373 for further details).
[0052] In the IPv6, the following three address scopes are
defined.
[0053] (1) Link Local Address
[0054] This is an address valid only within the same network link,
which has a prefix of 1111 1110 10 in the IPv6.
[0055] (2) Site Local Address
[0056] This is an address valid only within the same management
domain, which has a prefix of 1111 1110 11 in the IPv6.
[0057] (3) Global Address
[0058] This is an address which is unique over the entire
Internet.
[0059] In the example of FIG. 1, the mobile terminal device 20
connected to the mobile carrier network 12 can carry out
communications using (arbitrary address containing) the link local
address with respect to the server 4 (which is in a positional
relationship of being located) on the same network link as the
mobile terminal device 20, and communications using a site local
address (or a global address) with respect to a server (which is in
a positional relationship of being located) in the same management
domain as the mobile terminal device 20. On the other hand, the
mobile terminal device 20 connected to the mobile carrier network
12 will carry out communications using a global address with
respect to the server 8 (which is in a positional relationship of
being located) on the general Internet 7.
[0060] Now, the first communication interface 24 of this mobile
terminal device 20 can be always assigned with one or both of the
link local address and the site local address. The link local
address and the site local address will be derived from the prefix
defined in the IPv6 and the device ID of this mobile terminal
device 20. Note that it is also possible for the communication
service provider to assign arbitrary address as an address to be
used in the same network link. Also, which one of the link local
address alone, the site local address alone, and both the link
local address and the site local address is to be always assigned
can be determined according to the policy of the communication
service provider.
[0061] By always assigning the link local address alone, the site
local address alone, or both the link local address and the site
local address, the mobile terminal device 20 becomes always capable
of utilizing (carrying out communications for) on-link services
using (arbitrary address containing) the link local address (such
as the advertisement delivery from a specific wireless base station
group, for example), and/or services within domain which are
services of the service provider in this embodiment (such as
information service limited to the users of that service provider,
for example).
[0062] On the other hand, the global address to be assigned will be
generated from a network prefix delivered from the nearest neighbor
router device 4 and the ID information (EUI-64) of the mobile
terminal device 20, according to the "Stateless Address
Autoconfiguration" (RFC 2461) defined in the IPv6.
[0063] The basic procedure for the global address generation is as
follows. Namely, the router device 4 regularly broadcasts a router
advertisement message on-link, or the router device 4 returns a
response message upon receiving an inquiry message, and the mobile
terminal device 20 receives the router advertisement message, or
sends an inquiry message and receives the response message,
generates the global address by using the network prefix contained
in the received message, and transmits an address information
notification message containing the generated IPv6 address and a
MAC address to the router device 4 side.
[0064] Upon receiving the address information notification message,
the router device 4 makes an entry of a corresponding information
into a corresponding table called neighborhood cache (which
corresponds to the ARP table in the IPv4). As a result, the nearest
neighbor router device 4 will carry out the delivery of packets
destined to the mobile terminal device 20.
[0065] Note that the user may be allowed to freely carry out the
acquisition, setting and starting of the use of the IPv6 global
address, or the discarding, setting and ending of the use of the
IPv6 global address. Alternatively, it is also possible to use a
provision in which the processing for starting the use of the
global address is carried out when the user of the mobile terminal
device 20 activates an application that requires the global
address, and the processing for ending the use of that global
address is carried out when that application is finished.
[0066] In this embodiment, the assignment of the global address to
the second communication interface 25 of the mobile terminal device
20 is to be controlled using the above described address scope
function.
[0067] In the example of FIG. 1, when the same network link is set
to be within the home network 11, the mobile terminal device 20
connected to the home network 11 can carry out communications using
(arbitrary address containing) the link local address with respect
to a correspondent such as the other device 2 or the gateway device
1 through the home local network 3, and when the same site is set
to be within the ISP network 9, the mobile terminal device 20
connected to the home network 11 can carry out communications using
a site local address (or a global address) with respect to a
correspondent such as the server 10 within the ISP network 9. On
the other hand, the mobile terminal device 20 connected to the ISP
network 9 via the home network 11 will carry out communications
using a global address with respect to the server 8 on the general
Internet 7.
[0068] In the following, the operation in the case where the mobile
terminal device 20 moves toward the home network 11 while receiving
the service on the mobile carrier network 12 side by using the
assigned global address, and establishes a wireless link with the
home local network 3 to become a member of the home network 11,
will be described.
[0069] FIG. 4 shows an exemplary processing procedure of the mobile
terminal device 20 in this case.
[0070] First, the global address is assigned to the mobile terminal
device 20 at the mobile carrier network 12 side (step S11), and
when the mobile terminal device 20 approaches to the home network
11 while receiving the service on the mobile carrier network 12
side, the mobile terminal device 20 detects radio signals of the
other devices and establishes a link (step S12). This wireless link
establishing can be realized by a method specified for each radio
medium. At this point, if there is no particular job that uses the
local network on the Bluetooth side, it suffices to wait in the
wireless link established state.
[0071] Next, suppose that a service on the Bluetooth link side is
requested from the mobile terminal device 20. This request can be
made by a task unique to the mobile terminal device 20, or by
sending a result of a task on the mobile carrier network 12 side to
some device on the Bluetooth network side by utilizing a direct
bridging, for example.
[0072] At this point, the mobile terminal device 20 looks up a
resource (a desired service) to be accessed on the Bluetooth side
(step S13). In this case, it is possible to use various methods
such as a method using SDP (Service Discovery Protocol) defined in
the Bluetooth, a method using SLP (Service Location Protocol) for
looking up arbitrary service on the Internet, etc., and any
suitable combination can be used according to factors such as a
range to be looked up, a type of a service to be looked up, etc.
Here, it is assumed that the resource on the local Bluetooth link
will be looked up by using the SDP first, and if it cannot be
found, the wider range will be looked up by using the SLP. It is
also possible to use a configuration in which the gateway device 1
of FIG. 2 relays a query message for that purpose and becomes an
agent of the SLP itself, for example.
[0073] Next, the mobile terminal device 20 acquires a necessary
address (a link local address, a site local address or a global
address) according to a positional relationship between the mobile
terminal device 20 and the correspondent as obtained from the
service lookup result, and assigns it to the second communication
interface 25 (step S14). Then, the mobile terminal device 20
utilizes the desired service (step S15). Thereafter, the steps S13
to S15 will be repeated according to the need. However, the step
S14 can be skipped when the necessary address is already
acquired.
[0074] Next, the above described service lookup result will be
described for three different cases.
[0075] First, in the case where the resource is found to be a link
locally accessible one in the home local network 3 as a result of
the service lookup, the communications will be carried out by
assigning the link local IPv6 address to the home local network 3
side in the mobile terminal device 20. This procedure will be used
in the case of storing the image data downloaded from the mobile
carrier network 12 side into a disk for a PC as shown in FIG. 5,
for example.
[0076] Next, in the case where the resource is found to be a site
locally accessible one in the ISP network 9 on the home local
network 3 side as a result of the service lookup, the
communications will be carried out by assigning the site local IPv6
address to the home local network 3 side in the mobile terminal
device 20. This procedure will be used in the case of receiving the
service limited only to members of the ISP which is provided by the
server 10 in the ISP network 9 as shown in FIG. 6, for example.
[0077] On the other hand, in the case where the resource is found
to be located on the global Internet 7 as a result of the service
lookup, the communications will be carried out by assigning a
global IPv6 address to the home local network 3 side in the mobile
terminal device 20. At this point, the mobile terminal device 20
becomes capable of accessing the resource located on the global
Internet 7 either via the mobile carrier network 12, or via the
gateway device 1 through the home local network 3. This is the
state called "multi-home" in which the mobile terminal device 20
becomes a router having two communication interfaces which are
connected to different providers.
[0078] In the case of this multi-home state, both of the
communication interfaces can be made available. In such a case, one
communication interface can be used mainly while the other
communication interface is used as a back-up, and which
communication interface should be used mainly can be determined
according to factors such as the congestion state of each network,
the charging state of each network, etc.
[0079] For example, the home network 11 side can be selected when
the charge is much cheaper on the ISP network side (the fixed
network side), or the mobile carrier network 12 side can be
selected when the network speed is faster on the mobile carrier
network 12 side. Also, the communication interface to be selected
can be determined by accounting for a dynamically varying state,
instead of determining it fixedly. Such a policy can be set by the
user or a vendor of the terminal in advance into a control unit
(not shown) inside the mobile terminal device 20.
[0080] Note that the state or the like of the ISP network 9 side
may be acquired by inquiring it to the gateway device 1 or the
like, for example. Also, the mobile terminal device 20 itself may
maintain the charging condition or the like of the ISP network 9
side.
[0081] Similarly, the state or the like of the mobile carrier
network 12 side may be acquired by inquiring it to a prescribed
server device or the like on the mobile carrier network 12 side,
for example. Also, the mobile terminal device 20 itself may
maintain the charging condition or the like of the mobile carrier
network 12 side.
[0082] FIG. 7 shows an exemplary processing procedure of the mobile
terminal device 20 in this case. Namely, in the case where the
global address is available on both the mobile carrier network 12
side and the home network 11 side (step S21 YES, step S22 YES),
which one of the global address on the mobile carrier network 12
side and the global address on the home network 11 side should be
used is determined according to various factors (step S23).
[0083] Now, while the processing on the home local network 3 side
in the mobile terminal device 20 is carried out in this way, the
job on the mobile carrier network 12 side may be finished. This job
status on the mobile carrier network 12 side regarding the finished
state can be detected by regularly checking the active register 27
in the mobile terminal device 20. When all the jobs on the mobile
carrier network 12 side are finished, the entire network setting on
the mobile carrier network 12 side is released, such that the
necessary setting is concentrated into that on the home local
network 3 side. This measure is taken from a viewpoint of not
wasting the access channel resources unnecessarily.
[0084] FIG. 8 shows an exemplary processing procedure of the mobile
terminal device 20 in this case. Namely, when all the jobs on the
mobile carrier network 12 side are finished (step S31 YES), the
entire network setting on the mobile carrier network 12 side is
released (step S32).
[0085] Note that it is also possible to use a provision in which
the mobile terminal device 20 transmits a message for notifying the
finishing of all the services received via the mobile carrier
network 12 to the gateway device 1 through the home local network
3, and the gateway device 1 notifies a message for setting up a
global address (via the ISP network 9) to be set up on the home
local network 3 side to the mobile terminal device 20 upon
receiving the above message from the mobile terminal device 20 if
such a global address is not set up yet.
[0086] Now, it is also possible to use a provision in which the
network setting on the mobile carrier network 12 side is not
released but reserved as an emergency communication path for the
device 2 on the home local network 3 side to access the Internet 7
at a time of fault in the gateway device 1 or the ISP network 9,
for example. Even in this case, all the existing devices 2 are
initialized by the network setting on the home local network 3
side, so that they cannot use the channel of the mobile terminal
device 20 without a further change, and for this reason, there is a
need for the mobile terminal device 20 to function as a gateway
with respect to the devices 2 on the home local network 3 side by
carrying out the NAT/Proxy processing, etc.
[0087] FIG. 9 shows an exemplary processing procedure of the mobile
terminal device 20 in this case. Namely, when the mobile terminal
device 20 is going to be a gateway of the home network side (step
S41 YES), the NAT/Proxy processing, etc., are carried out (step
S42).
[0088] Also, in practice, the mobile terminal device 20 establishes
the network setting on the home local network 3 side gradually, so
that it is possible to make a transition to the state of using a
link on the home local network 3 side regardless of the
communication interface on the mobile carrier network 12 side.
[0089] Also, in the above, it is assumed that the communication
interface to be used for the application is not to be changed
during the communications for that application, but it is also
possible to change the communication interface at appropriate
timing during the communications for that application (from the
mobile carrier network 12 side to the home local network 3 side,
for example).
[0090] Note that, for the job that requires the link local or site
local resource access' on the mobile carrier network 12 side, the
communication interface on the mobile carrier network 12 side is to
be used until this job is finished (or until this job is
cancelled).
[0091] Now, using the specification of the Mobile IPv6 which is
currently under the standardization process by the IETF, it is
possible to guarantee the mobility by regarding the mobile terminal
device 20 that is actually connected to the mobile carrier network
12 side as having moved to the home local network 3 side. Here, a
method for switching the belonging network according to the Mobile
IPv6 will be described with references to FIGS. 10A and 10B.
[0092] FIG. 10A shows an exemplary packet header in this case,
which contains a source address (CN), a destination address (addr1)
and a destination option (via addr2). Here, CN is a global address
of the correspondent, addr1 is a global address of the mobile
terminal device 20 on the mobile carrier network 12 side, and addr2
is a global address of the mobile terminal device 20 on the home
local network 3 side. Also, the destination option specifies a
location through which the packet should be transferred.
[0093] Using the destination option of the IPv6, as shown in FIG.
10B, a packet transmitted from a correspondent 30 will be
controlled to be transferred to the original address on the mobile
carrier network 12 side via the address on the home local network 3
side. Then, in practice, the fact that this packet is destined to
the mobile terminal device 20 is ascertained when the packet is
captured at the address on the mobile carrier network 12 side, and
the packet communication using a direct route becomes possible as
the mobile terminal device 20 acquires this packet.
[0094] In the above, the case where the mobile terminal device 20
moves from the mobile carrier network 12 side into the home local
network 3 side has been described, but the reverse case where the
mobile terminal device 20 moves from the home local network 3 side
out to the mobile carrier network 12 side can also be controlled
similarly. Namely, the mobile terminal device 20 can establish a
wireless link with the mobile carrier network 12 side, assign the
necessary IPv6 addresses according to the address scopes of the
necessary resources, and concentrates the setting to that of the
mobile carrier network 12 side by releasing the address setting on
the home local network 3 side when the jobs on the home local
network 3 side are eventually finished. Also, the route selection
policy in the case of becoming the multi-home state in a course of
this operation can be determined similarly.
[0095] Also, in the above, it is assumed that the mobile terminal
device 20 has the ordinary voice communication function, but the
mobile terminal device 20 may have communication functions for
information in other forms such as text communications in addition
to or instead of the ordinary voice communication function. The
mobile terminal device 20 may be a device which is capable of
utilizing only the Internet service. The similar modifications are
also possible with respect to the services provided by the
communication service provider.
[0096] As described, according to the present invention, in the
case where the mobile terminal device moves into the home local
network while carrying out communications in the mobile carrier
network, it is possible to construct the home local network side
setting in the mobile terminal device phase by phase, according to
the resources that become necessary in the home local network.
[0097] Also, in the case where the mobile terminal device
temporarily becomes the so called multi-home state in which the
IPv6 global addresses are assigned to both the home local network
and the mobile carrier network, which one of the two communication
interfaces should be used mainly can be determined appropriately by
accounting for the user's preference regarding the network state,
the charging condition, etc.
[0098] In addition, in the case where the communication jobs on the
mobile carrier network side are finished, the mobile terminal
device can release the network setting immediately such that all
communications can be concentrated to those via the home local
network.
[0099] Furthermore, these setting conditions can be finely adjusted
according to the user's preference, such that it is possible to
freely devise a policy (within a range of violating the scope rule
for each application, for example) such as that all the jobs are
re-constructed as the home local network based ones immediately
once the wireless link with the home local network is established,
as long as no service dependent on the mobile carrier network side
is received, for example.
[0100] Thus according to the present invention, the mobile terminal
device can judge whether the resource necessary on the local
network side is a resource that is on-link (a device with which
communications can be carried out directly), or a resource that is
closed within the same site, or a resource other than these, by
using the service lookup or the like, and assign the IPv6 address
of the scope corresponding to that location to the local network
side.
[0101] When the required resource is on the global Internet, it is
accessible from both the mobile communication network and the fixed
network, and it is possible to judge whether the mobile terminal
device is to become a router in the multi-home state or the access
is to be continued on the mobile communication network side alone,
for example, by accounting for the network state, the charging
condition, etc.
[0102] It is also possible to update the network setting such that
the Internet service can be continued by the fixed communication
network side alone by releasing the address on the mobile
communication network side, when all the services of the mobile
communication network are finished as the time elapses, for
example. It is also possible to carry out the similar control even
in the case of making a transition from the fixed communication
network to the mobile communication network in the reverse
direction.
[0103] Consequently, according to the present invention, in the
case where the mobile terminal device moves into the local network
while receiving the communication services on the mobile
communication network side, it is possible to determine the address
setting, the communication route selection, etc., on the local
network side appropriately by accounting for the user's policy, the
necessary resources, etc.
[0104] Note that the home network used in the above described can
be replaced by any other local network without affecting the
applicability of the present invention.
[0105] Note also that, in the present invention, the existing IPv6
devices can be used without requiring any modification, and the
conventional IPv6 addressing architecture can be used without any
change. Consequently, it is advantageous in terms of the
compatibility with the existing devices.
[0106] Note also that the present invention can be easily expanded
according to the network management policies of the various mobile
carriers. The present invention is also applicable not only to the
IPv6 but also to the packet communications using the cellular
phones that are proposed recently.
[0107] It is to be noted that the above described embodiments
according to the present invention may be conveniently implemented
using a conventional general purpose digital computer programmed
according to the teachings of the present specification, as will be
apparent to those skilled in the computer art. Appropriate software
coding can readily be prepared by skilled programmers based on the
teachings of the present disclosure, as will be apparent to those
skilled in the software art.
[0108] In particular, each of the gateway device and the mobile
terminal device of the above described embodiment can be
conveniently implemented in a form of a software package.
[0109] Such a software package can be a computer program product
which employs a storage medium including stored computer code which
is used to program a computer to perform the disclosed function and
process of the present invention. The storage medium may include,
but is not limited to, any type of conventional floppy disks,
optical disks, CD-ROMs, magneto-optical disks, ROMs, RAMs, EPROMs,
EEPROMs, magnetic or optical cards, or any other suitable media for
storing electronic instructions.
[0110] It is also to be noted that, besides those already mentioned
above, many modifications and variations of the above embodiments
may be made without departing from the novel and advantageous
features of the present invention. Accordingly, all such
modifications and variations are intended to be included within the
scope of the appended claims.
* * * * *